Saudi Arabia, UAE and Bahrain join Israel in applauding US president's decision to pull out of the Iran nuclear deal.

President Donald Trump has decided to withdraw the United States from a multinational nuclear agreement with Iran, saying the deal is "defective at its core" and announcing "the highest level of sanctions" against Tehran.

Under the deal signed in Vienna with six world powers - the US, UK, France, Germany, Russia, China and the European Union - Iran scaled back its uranium enrichment programme and promised not to pursue nuclear weapons.

In exchange, international sanctions were lifted, allowing it to sell its oil and gas worldwide. However, secondary US sanctions remain. United Nations inspectors have repeatedly confirmed Iran's compliance with the deal.

Trump said the agreement - also known as the Joint Comprehensive Plan of Action (JCPOA) - was a "horrible one-sided deal that should never ever have been made".

In response, Iranian President Hassan Rouhani said Tehran would bypass Washington and negotiate with the other signatories of the deal, calling the US move "unacceptable".

Following Trump's speech on Tuesday, there was an immediate reaction by world leaders, including the other parties to the landmark deal.

Here's a round-up of statements from around the world:

France, Germany and UK

"France, Germany and the UK regret the US decision to leave the JCPOA," French President Emmanuel Macron, a champion of the deal, wrote on Twitter.

"The nuclear non-proliferation regime is at stake," he added.

"We will work collectively on a broader framework, covering nuclear activity, the post-2025 period, ballistic activity, and stability in the Middle East, notably Syria, Yemen and Iraq."

France's Foreign Minister, Jean-Yves Le Drian, said in a radio interview "the deal is not dead". He said Europe's foreign leaders will meet next week with representatives from Iran to talk about the future of the JCPOA.

Germany also reiterated it also wants to uphold the deal. Foreign Minister Heiko Maas said "the deal makes the world safer", adding that Germany could find no legitimate reason for pulling out of the deal.

On Twitter, UK Foreign Minister Boris Johnson said he regretted the US no longer taking part in the nuclear deal.

"UK remains strongly committed to the JCPoA, and will work with E3 partners and the other parties to the deal to maintain it," he added.

Deeply regret US decision to withdraw from the Iran nuclear deal. UK remains strongly committed to the JCPoA, and will work with E3 partners and the other parties to the deal to maintain it. Await more detail on US plan.

The top European Union diplomat, Federica Mogherini, called on the international community to preserve the Iran nuclear deal.

"The EU will remain committed to the continued full and effective implementation of the nuclear deal," Mogherini said from Brussels.

"We fully trust the work, competence and autonomy of the International Atomic Energy Agency that has published 10 reports certifying that Iran has fully complied with its commitments.

"The lifting of nuclear-related sanctions is an essential part of the agreement. The EU has repeatedly stressed that the lifting of nuclear-related sanctions has a positive impact not only on trade and economic relations with Iran, but also mainly, [it has] crucial benefits for the Iranian people."

China

China, one of the countries that signed the JCPOA, joined the Europe its response, saying the country is committed to protecting the deal as it stands.

China's special envoy to the Middle East, Gong Xiaosheng, said in a press conference in Iran the agreement promoted peace.

"Having a deal is better than no deal. Dialogue is better than confrontation." he said according to Xinhua news agency.

Russia

Russia, one of the signatories of the deal, said it will try to keep the deal functioning despite Tuesday's decision by the US.

Yevgeny Serebrennikov, first deputy head of the defense and security committee in the Russian Upper House of Parliament also told RIA news agency Trump's decision could put the nuclear talks between the US and North Korea at risk.

"Israel fully supports President Trump's bold decision today to reject the disastrous nuclear deal with the terrorist regime in Iran.

"Israel has opposed the nuclear deal from the start because we said that rather than blocking Iran's path to a bomb, the deal actually paves Iran's path to an actual arsenal of nuclear bombs and this within a few years time.

"The removal of sanctions under the deal has already produced disastrous results. The deal didn't push war further away, it actually brought it closer."

Barack Obama

In a written statement, the former US president, whose administration negotiated and signed the deal, issued a list of points as to why Trump's decision is "so misguided". "The reality is clear. The JCPOA is working - that is a view shared by our European allies, independent experts, and the current US Secretary of Defence," Barack Obama wrote.

"The JCPOA is in America's interest - it has significantly rolled back Iran's nuclear programme. And the JCPOA is a model for what diplomacy can accomplish - its inspections and verification regime is precisely what the United States should be working to put in place with North Korea.

"Indeed, at a time when we are all rooting for diplomacy with North Korea to succeed, walking away from the JCPOA risks losing a deal that accomplishes - with Iran - the very outcome that we are pursuing with the North Koreans."

Saudi Arabia, UAE and Bahrain

Saudi Arabia, a regional rival of Iran and longtime US ally, said that it supports Trump's decision.

"The kingdom supports and welcomes the steps announced by the US president toward withdrawing from the nuclear deal ... and reinstating economic sanctions against Iran," the Saudi foreign ministry said.

Riyadh's allies in the Gulf - the United Arab Emirates and Bahrain - also welcomed Trump's decision.

United Nations

The United Nations Secretary-General Antonio Guterres said in a statement that he was "deeply concerned", urging the remaining parties of the deal to abide by their commitments.

"It is essential that all concerns regarding the implementation of the plan be addressed through the mechanisms established in the JCPOA. Issues not directly related to the JCPOA should be addressed without prejudice to preserving the agreement and its accomplishments," Guterres said.

Australia and Japan

Both Australia and Japan have also said they regret the US decision. Australia's Prime Minister Malcolm Turnbull called on all sides to use restraint in their response.

Japan's Foreign Minister Taro Kono issued a statement saying Japan hopes the pulling out does not affect Iran's capabilities of adhering to the JCPOA.

"We hope that the countries involved will continue to deal with the issue in a constructive manner," he added.

Turkey

In a response to the news, Turkey called Trump's decision "an unfortunate step", adding that the deal was an important step to prevent nuclear proliferation.

"The Joint Comprehensive Plan of Action must be protected and continue to be implemented in full transparency, uninterrupted and complete, under the control of the IAEA," a statement on the foreign ministry's website said.

Ibrahim Kalin, spokesperson for President Recep Tayyip Erdogan, said on Twitter the US withdrawal could put the world at risk.

"Turkey maintains its firm stance against all nuclear weapons regardless of who owns them,” he added.

John Kerry

The former US secretary of state also issued a statement in support of the deal.

"No rhetoric is required. The facts speak for themselves. Instead of building on unprecedented non-proliferation verification measures, this decision risks throwing them away and dragging the world back to the brink we faced a few years ago.

"The extent of the damage will depend on what Europe can do to hold the nuclear agreement together, and it will depend on Iran's reaction. America should never have to outsource those stakes to any other country. This is not in America's interests. We should all hope the world can preserve the nuclear agreement."